Solid state power controllers for controlling the flow of power to various components require a ground fault interrupt to open the power supply if undesired conditions are sensed. The use of such ground fault interrupts is becoming particularly important for solid state power controllers utilized with components in an aircraft.
It is known in a standard ground fault interrupt, that the current on the power supply lines is summed and compared to a maximum. If the summed currents on the several power supply lines exceed a predetermined maximum, then a ground fault interrupt opens to open a circuit and prevent the flow of further power.
Several distinct types of power supplies are commonly utilized. As an example, there are three-phase power supplies both with and without a fourth neutral wire. Further, there are single phase power supplies, or dual phase power supplies. Each of these different types of power supply might be associated with a particular optimum method of sensing a current which should trigger a ground fault interrupt.